An integrated circuit (IC) die is generally packaged to protect the die from external contamination or physical damage. As demand for high performance devices grows, more than one IC die may be included in a single IC package to meet the demand of high speed applications. In a multi-die IC package, two (or more) IC dies may be placed adjacent to each other on an interposer structure placed on top of a package substrate. Such an IC package is commonly referred to as a 2.5-dimensional (2.5D) IC package.
Typically, in a 2.5D IC package, through silicon vias (TSVs) are formed in the interposer to transmit signals from the IC dies on top of the interposer to the package substrate at the bottom of the interposer. Metal traces are also formed in the interposer to transmit signals between the IC dies that are placed on top of the interposer. However, in order to accommodate the IC die(s) on top of the interposer, a relatively large (at least as wide as or wider than the IC die or dies placed on top) interposer structure is needed.
As demand for high speed applications grows, higher-density package substrates with narrower trace widths are needed to support such applications. Such a package substrate (i.e., a package substrate with a relatively high routing density) is generally more costly compared to a package substrate with a lower routing density.
As an alternative, a silicon bridge structure may be formed or placed in the package substrate to provide high density chip-to-chip connections. The silicon bridge structure is typically smaller in size compared to an interposer and may therefore be a more cost-effective solution. However, it may not be as power efficient as there are typically no direct power connections from the silicon bridge to the IC die(s). This may lead to a higher voltage drop due to the relatively longer traces or interconnect paths needed for power or ground connections. Furthermore, there may be routing congestion in the device since power connections may need to be routed from the center of the IC die(s) to other parts of package substrate away from the silicon bridge structure.
It is within this context that the embodiments described herein arise.